A diploma is the final step in a traditional education, but in the DIY world, credit comes from the reputation you build by doing good work and demonstrating it to others in a community. The rules of this world are informal and evolving, but joining and demonstrating value to a network is not optional for success in the 21st century. Here's a guide to becoming a valued part of a network.

Pick your path. The community you want to be a part of should reflect your passion. If you don’t see it among the ones listed below, search until you find it, or form your own by expanding out from your personal learning network.

Show up. Your profile on an online network must include samples of your work, whether it’s writing, photographs, video, audio, or code, or at least written descriptions with photos of projects you’ve done. The more time you spend presenting yourself and sharing stuff, the more you’ll show up.

Help others. Good citizenship in a reputation-based network means being helpful in any way you can: pitching in on another’s project, offering feedback, publicity, support, or just answering questions from newcomers. The golden rule rules.

Meet up. Whether it’s a local mixer at a bar, panel discussion, workshop, or a big national or international conference, shared-interest communities like to meet up in person. This is the way to solidify your connections and find new opportunities. Go.

Keep an ear out for opportunities. Some networks have job boards, others just have informal connections. Some one-year courses at community colleges also are designed to prepare you for certificates.

A Few Networks For:

ProgrammersGithub: Chris Wanstrath and his cofounders didn’t start Github in 2008 with the idea of creating a professional community for software developers. They simply needed a code repository—a place to publicly place open-source software code so teams could work together more easily. They created the largest software code-hosting site in the world, with 750,000 members hosting 2 million repositories. “A Github profile shows off what a person has done, what projects they have contributed to, how active are they at a high level,” Chris says. “On Github you’re not saying how great you are, you’re showing it. I think that’s really important."

Stack Overflow: Stack Overflow is another site for programmers. It’s based on asking and answering questions, meaning it’s a great resource for learning how to program, but it can also be a way of building a reputation.

Artists, Graphic Designers, IllustratorsBehance: Behance allows all kinds of creative workers, whether photographers, graphic designers, or illustrators, to upload multimedia portfolios. These can be seen, commented on, and voted up or down by the creative community—portfolios that get more recognition get promoted on the site and become easier to find. Top companies like Saatchi & Saatchi, JWT, R/GA, Crispin, Ogilvy Nike, Apple, Facebook, Zappos, Target, and Netflix have all actively recruited from the site.

FilmmakersVimeo: Vimeo is a community for people who make videos. You can share videos, “like” others’ videos, collaborate on projects, join groups with shared interests, and watch lots of tutorials.

MusiciansSoundcloud: Soundcloud is a place to easily upload and share your music all over the web. Others can post comments. You can post a “bandpage” and join groups of musicians in similar styles.

Myspace: Myspace is still very popular for bands who want to post music, collect fans, and share information on upcoming concerts.

Crafty TypesEtsy: Etsy is primarily a marketplace for people who sell handmade things, but it has many community features, including an online forum, “teams” who sell similar things and band together to co-promote, chat rooms, online workshops, plus meetups and events in some cities.

Writers, Editors, JournalistsMediabistro: Mediabistro is a community I joined when I first became a freelance writer. They offer pro- files where you can show off your writing, workshops, classes and other events, job listings, and more. Many of the benefits require paying a $55 annual fee.

Romenesko: On the website of the Poynter Institute, a nonprofit dedicated to journalism education, you can post your resume; find jobs and follow industry news; and take part in self-directed and group online courses, podcasts and video tutorials.

Event Planners, Artists, Activists, Product DesignersKickstarter: Kickstarter is a slightly different kind of community. It’s a place to post and solicit donations from friends, family, and the community at large to fund your creative projects. This could be a design you want to market, a benefit concert, a book you want to publish, or even that cross-country trip you and your buds have been dreaming about. There are some stakes built in: you post a target amount and a deadline, and if you miss the target, you don’t get any money. Browsing the site will bring you lots of inspiration that you can go out and make your dreams happen.